Multicast streaming services allow users on a network to collectively share a network resource, such as streaming video, or an Internet radio show. For example, Bonjour by Apple, Inc. implements zero-configuration networking to easily access shared resources on a local network, such as a printer or video projector in an office. Multicast is the underlying technology enabling these streaming services.
Although multicast can be efficient by making streams available to any interested station, the technique also has some inherent inefficiencies. Copies of data packets are transmitted to each network device in a local network to make streaming services available at any point of the network. At times when few stations are subscribed to a multicast service, or when certain parts of the network are undersubscribed, network resources are wasted at devices and across the communication channels. In contrast to multicast, unicast transmits a single data packet from a source to a specific destination rather to copies of a data packet to many destinations (i.e., one-to-many rather than one-to-one). Thus, unicast can be more efficient for small audiences.
An SDN-enabled local network centrally manages layer-2 network functionality with respect to the OSI layers. In other words, routers, access points and other network components, devices or applications cede local routing decisions in favor of a centralized authority for implementing network wide policies. Further, real-time network conditions can be monitored on a global basis and adjustments to local layer 2 routing can be made in response.
What is needed is a robust technique to efficiently manage multicast service discovery, as well as efficiently manage service streaming, in SDN-enabled networks.